Owing to the advancement of the science and technologies, more and more touch screen terminals have been widely used in people's daily life, for example, mobile phones, tablet computers and digital photo frames, etc. In order to prevent the touch screen terminals from being accidentally activated or from being activated for a long time to cause power consumption, the system of the touch screen terminals may be set in such a way that the display screen of the touch screen automatically enters into a locked operation mode when they are not used by users. Then, when it is necessary to activate the display screen of the touch screen that is in the locked operation mode, typically the display screen is unlocked by a slide unlocking operation or by use of a stationary keypad.
However, for the conventional unlocking manner, the unlocking interface is relatively monotonous and cannot satisfy the requirements for personalization, and this decreases the flexibility of the unlocking operation. Furthermore, the slide unlocking operation usually requires continuous sliding from the unlocking start point to the unlocking finish point in order to smoothly accomplish the unlocking operation, which is inconvenient for the users.